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Abstract Background This paper aims at analysing the impact of partial non-response in the association between urban environment and mental health in Brussels. The potential threats of the partial non-response are biases in survey estimates and statistics. The effect of non-response on statistical associations is often overlooked and evidence in the research literature is lacking. Methods Data from the Belgian Health Interview Survey 2008 and 2013 were used. The association between non-response and potential determinants was explored through logistic regressions. Results Participants with low income, low educational levels, lower or higher age or in households with children were less likely to respond. When adjusting for socio-economic variables, non-response was higher in areas which are less vegetated, more polluted or more urbanised. Because the determinants of non-response and depressive disorders were similar, it is reasonable to assume that there will be more people with mental health problems among the non-respondents. And because more non-responses were found in low vegetation areas, the protective association between green spaces and mental health may be underestimated. Conclusion Our capacity to measure the association between the urban environment and health is affected by non-response in surveys. The non-random spatial and socio-economic distribution of this bias affects the research findings.

Objectives: This study aimed to assess the efficacy and safety of 300 mg camostat mesylate three times daily in a fasted state to treat early phase COVID-19 in an ambulatory setting. Methods: We conducted a phase II randomized controlled trial in symptomatic (maximum 5 days) and asymptomatic patients with confirmed COVID-19 infection. Patients were randomly assigned in a 2:1 ratio to receive either camostat mesylate or a placebo. Outcomes included change in nasopharyngeal viral load, time to clinical improvement, the presence of neutralizing antibodies, and safety. Results: Of 96 participants randomized between November 2020 and June 2021, analyses were performed on the data of 90 participants who completed treatment (N = 61 camostat mesylate, N = 29 placebo). The estimated mean change in cycle threshold between day 1 and day 5 between the camostat and placebo group was 1.183 (P = 0.511). The unadjusted hazard ratio for clinical improvement in the camostat group was 0.965 (95% confidence interval, 0.480-1.942, P = 0.921 by Cox regression). The percentage distribution of the 50% neutralizing antibody titer at day 28 visit and frequency of adverse events were similar between the two groups. Conclusion: Under this protocol, camostat mesylate was not found to be effective as an antiviral drug against SARS-CoV-2.Trial registration: ClinicalTrials.gov NCT04625114; November 12, 2020.

Alzheimer's disease is the commonest form of dementia. It is likely that a lack of clearance of amyloid beta (Aβ) results in its accumulation in the parenchyma as Aβ oligomers and insoluble plaques, and within the walls of blood vessels as cerebral amyloid angiopathy (CAA). The drainage of Aβ along the basement membranes of blood vessels as intramural periarterial drainage (IPAD), could be improved if the driving force behind IPAD could be augmented, therefore reducing Aβ accumulation. There are alterations in the composition of the vascular basement membrane in Alzheimer's disease. Lysyl oxidase (LOX) is an enzyme involved in the remodelling of the extracellular matrix and its expression and function is altered in various disease states. The expression of LOX is increased in Alzheimer's disease, but it is unclear whether this is a contributory factor in the impairment of IPAD in Alzheimer's disease. The pharmacological inhibition of LOX may be a strategy to improve IPAD and reduce the accumulation of Aβ in the parenchyma and within the walls of blood vessels.

Abstract Background The COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has presented itself as one of the most important health concerns of the 2020’s, and hit the geriatric population the hardest. The presence of co-morbidities and immune ageing in the elderly lead to an increased susceptibility to COVID-19, as is the case for other influenza-like illnesses (ILI) or acute respiratory tract infections (ARI). However, little is known, about the impact of a previous or current infection on the other in terms of susceptibility, immune response, and clinical course. The aim of the “Prior Infection with SARS-COV-2” (PICOV) study is to compare the time to occurrence of an ILI or ARI between participants with a confirmed past SARS-CoV-2 infection (previously infected) and those without a confirmed past infection (naïve) in residents and staff members of nursing homes. This paper describes the study design and population characteristics at baseline. Methods In 26 Belgian nursing homes, all eligible residents and staff members were invited to participate, resulting in 1,226 participants. They were classified as naïve or previously infected based on the presence of detectable SARS-CoV-2 antibodies and/or a positive RT-qPCR result before participation in the study. Symptoms from a prior SARS-CoV-2 infection between March and August 2020 were compared between previously infected residents and staff members. Results Infection naïve nursing home residents reported fewer symptoms than previously infected residents: on average 1.9 and 3.1 symptoms, respectively (p = 0.016). The same effect was observed for infection naïve staff members and previously infected staff members (3.1 and 6.1 symptoms, respectively; p

Abstract Background The severity of an influenza infection is influenced by both host and viral characteristics. This study aims to assess the relevance of viral genomic data for the prediction of severe influenza A(H3N2) infections among patients hospitalized for severe acute respiratory infection (SARI), in view of risk assessment and patient management. Methods 160 A(H3N2) influenza positive samples from the 2016–2017 season originating from the Belgian SARI surveillance were selected for whole genome sequencing. Predictor variables for severity were selected using a penalized elastic net logistic regression model from a combined host and genomic dataset, including patient information and nucleotide mutations identified in the viral genome. The goodness-of-fit of the model combining host and genomic data was compared using a likelihood-ratio test with the model including host data only. Internal validation of model discrimination was conducted by calculating the optimism-adjusted area under the Receiver Operating Characteristic curve (AUC) for both models. Results The model including viral mutations in addition to the host characteristics had an improved fit ( $${X}^{2}$$ X 2 =12.03, df = 3, p = 0.007). The optimism-adjusted AUC increased from 0.671 to 0.732. Conclusions Adding genomic data (selected season-specific mutations in the viral genome) to the model containing host characteristics improved the prediction of severe influenza infection among hospitalized SARI patients, thereby offering the potential for translation into a prospective strategy to perform early season risk assessment or to guide individual patient management.

Abstract Background Mental health disorders appear as a growing problem in urban areas. While common mental health disorders are generally linked to demographic and socioeconomic factors, little is known about the interaction with the urban environment. With growing urbanization, more and more people are exposed to environmental stressors potentially contributing to increased stress and impairing mental health. It is therefore important to identify features of the urban environment that affect the mental health of city dwellers. The aim of this study was to define associations of combined long-term exposure to air pollution, noise, surrounding green at different scales, and building morphology with several dimensions of mental health in Brussels. Methods Research focuses on the inhabitants of the Brussels Capital Region older than 15 years. The epidemiological study was carried out based on the linkage of data from the national health interview surveys (2008 and 2013) and specifically developed indicators describing each participant’s surroundings in terms of air quality, noise, surrounding green, and building morphology. These data are based on the geographical coordinates of the participant’s residence and processed using Geographical Information Systems (GIS). Mental health status was approached through several validated indicators: the Symptom Checklist-90-R subscales for depressive, anxiety and sleeping disorders and the 12-Item General Health Questionnaire for general well-being. For each mental health outcome, single and multi-exposure models were performed through multivariate logistic regressions. Results Our results suggest that traffic-related air pollution (black carbon, NO2, PM10) exposure was positively associated with higher odds of depressive disorders. No association between green surrounding, noise, building morphology and mental health could be demonstrated. Conclusions These findings have important implications because most of the Brussel’s population resides in areas where particulate matters concentrations are above the World Health Organization guidelines. This suggests that policies aiming to reduce traffic related-air pollution could also reduce the burden of depressive disorders in Brussels.

Each year, seasonal influenza results in high mortality and morbidity. The current classification of circulating influenza viruses is mainly focused on the hemagglutinin gene. Whole-genome sequencing (WGS) enables tracking mutations across all influenza segments allowing a better understanding of the epidemiological effects of intra- and inter-seasonal evolutionary dynamics, and exploring potential associations between mutations across the viral genome and patient’s clinical data. In this study, mutations were identified in 253 Influenza A (H3N2) clinical isolates from the 2016-2017 influenza season in Belgium. As a proof of concept, available patient data were integrated with this genomic data, resulting in statistically significant associations that could be relevant to improve the vaccine and clinical management of infected patients. Several mutations were significantly associated with the sampling period. A new approach was proposed for exploring mutational effects in highly diverse Influenza A (H3N2) strains through considering the viral genetic background by using phylogenetic classification to stratify the samples. This resulted in several mutations that were significantly associated with patients suffering from renal insufficiency. This study demonstrates the usefulness of using WGS data for tracking mutations across the complete genome and linking these to patient data, and illustrates the importance of accounting for the viral genetic background in association studies. A limitation of this association study, especially when analyzing stratified groups, relates to the number of samples, especially in the context of national surveillance of small countries. Therefore, we investigated if international databases like GISAID may help to verify whether observed associations in the Belgium A (H3N2) samples, could be extrapolated to a global level. This work highlights the need to construct international databases with both information of viral genome sequences and patient data.

Abstract Accessory cavitated uterine mass (ACUM) is a very rare, underdiagnosed pathology. It is treated with radical surgery, which results in uterine scarring. Here, we describe the first case of ethanol sclerotherapy of an ACUM, modeled on the treatment of recurring endometrioma. Ethanol sclerotherapy avoids uterine scarring and the secondary risk of uterine rupture and enables the rapid achievement of pregnancy.

Abstract Many times the nodes of a complex network, whether deliberately or not, are aggregated for technical, ethical, legal limitations or privacy reasons. A common example is the geographic position: one may uncover communities in a network of places, or of individuals identified with their typical geographical position, and then aggregate these places into larger entities, such as municipalities, thus obtaining another network. The communities found in the networks obtained at various levels of aggregation may exhibit various degrees of similarity, from full alignment to perfect independence. This is akin to the problem of ecological and atomic fallacies in statistics, or to the Modified Areal Unit Problem in geography. We identify the class of community detection algorithms most suitable to cope with node aggregation, and develop an index for aggregability, capturing to which extent the aggregation preserves the community structure. We illustrate its relevance on real-world examples (mobile phone and Twitter reply-to networks). Our main message is that any node-partitioning analysis performed on aggregated networks should be interpreted with caution, as the outcome may be strongly influenced by the level of the aggregation.

Abstract Nonpuerperal uterine inversion is a very rare event. We reported on the first ever case of nonpuerperal uterine inversion due to adenomyosis. Magnetic resonance imaging is recommended in cases with an unusual vaginal mass, so that this possible uterine etiology can be taken into consideration.

This paper aims at proposing a new delimitation of the morphological agglomeration of Valencia (Spain) using a method based on fractal geometry (MorphoLim) and comparing the obtained results with standard delineations. The urban agglomeration of Valencia is located on the Mediterranean coast and is experiencing a strong urban growth by spatial dispersion and by multiplication of building floors. The originality of this paper lies in the application of a method capable of taking into account the diffusion for several heights of buildings, which allows to take into account the specificities of Valencia. The introduction of the third dimension offers a new perspective in the morphological analysis of urban spaces.

As part of a broader multidisciplinary research project dealing with the association between health and green/blue environments, this paper aims at exploring the spatial variation of medication reimbursements within Belgium. These data were potentially and a priori considered as a proxy for health. This paper is purely exploratory: statistical maps, correlations, PCAs and cluster analyses corroborate the results. Five groups of medications prescribed for health disorders associated with the environment have been selected. We show that – at the level of the municipalities – the spatial distributions of the five medication groups are positively correlated to each other (medication consumption co-vary positively in space, whatever their type), but are independent of the environmental and socio-economic conditions measured. Against our expectation, they prove to be negatively correlated to air pollution and green spaces. Strikingly, the spatial distribution of medication prescriptions follows the linguistic border between Flanders and Wallonia. This implies that the observed differences are mainly due to administrative/political regional differences in terms of health policies, medical schools, pharmaceutical commercial activities, etc. that are hard to quantify (no data, diversity of actors) but should be taken into account in any further explanatory model. Medication reimbursements data correspond to a new type of data, and despite their potential attractiveness for health analyses, extreme care has to be taken when interpreting their spatial variation and their link to health.

Abstract Xanthogranulomatous endometritis is a rare benign pathology mimicking endometrial carcinoma.

Abstract Background Wheezing among children below the age of six (pre-schoolers) is common and often triggered by environmental factors. Moreover, evidence on which to base recommendations for its management is limited, resulting in high numbers of prescriptions and costs. This study aims to describe the spatial differences in asthma medication sales for children aged 0 to 5 years in Belgium, and to evaluate the correlations with socio-economic and environmental factors.. Methods This ecological study includes information on prescribed and sold asthma medication (R03 ATC code) for all the pre-schoolers registered in Belgium, aggregated at the municipality and smaller administrative levels, in 2014. A case was defined as a pre-schooler having purchased prescribed R03 medication at least once in 2014. We mapped the number of cases, the prevalence of medication purchase (n cases/n registered pre-schoolers) and the costs per case (€) at different administrative levels. We used symbol maps for the number of cases and choropleth maps for prevalence and costs per case using Jenks discretization at the municipal level, and standard deviation at finer scales. Finally, we calculated Pearson correlations of medication prevalence and costs per case with socio-economic (population density and area median income), and environmental (PM10, pig density and green spaces) factors. Results The number of medication purchases was large in cities. The prevalence of purchase was higher in the French- than in the Flemish-speaking region, showing a sharp linguistic border. The cost per case was concentrated in one specific region in the north-west of Belgium. We found inverse correlations of prevalence of purchase with area median income and PM10 concentrations, and positive moderate correlations with green spaces and pig density. The costs per case were weakly but positively correlated with PM10 concentrations and green spaces, and moderately with pig density. Conclusions In Belgium, the geographical distribution of purchases of prescribed asthma medication for pre-schoolers is only weakly correlated with some environmental factors. The existence of clear differences in prevalence of purchase between Flemish and French-speaking regions suggests that the observed geographical distribution is strongly driven by regional differences in medical practice.

Background: Epidemiological studies suggest that residing close to green space reduce mortality rates. We investigated the relationship between long-term exposure to residential green space and non-accidental and cardio-respiratory mortality. Methods: We linked the Belgian 2001 census to population and mortality register follow-up data (2001–2011) among adults aged 30 years and older residing in the five largest urban areas in Belgium (n = 2,185,170 and mean follow-up time 9.4 years). Residential addresses were available at baseline. Exposure to green space was defined as 1) surrounding greenness (2006) [normalized difference vegetation index (NDVI) and modified soil-adjusted vegetation index (MSAVI2)] within buffers of 300 m, 500 m, and 1000 m; 2) surrounding green space (2006) [Urban Atlas (UA) and CORINE Land Cover (CLC)] within buffers of 300 m, 500 m, and 1000 m; and 3) perceived neighborhood green space (2001). Cox proportional hazards models with age as the underlying time scale were used to probe into cause-specific mortality (non-accidental, respiratory, COPD, cardiovascular, ischemic heart disease (IHD), and cerebrovascular). Models were adjusted for several sociodemographic variables (age, sex, marital status, country of birth, education level, employment status, and area mean income). We further adjusted our main models for annual mean (2010) values of ambient air pollution (PM2.5, PM10, NO2 and BC, one at a time), and we additionally explored potential mediation with the aforementioned pollutants. Results: Higher degrees of residential green space were associated with lower rates of non-accidental and respiratory mortality. In fully adjusted models, hazard ratios (HR) per interquartile range (IQR) increase in NDVI 500 m buffer (IQR: 0.24) and UA 500 m buffer (IQR: 0.31) were 0.97 (95%CI 0.96–0.98) and 0.99 (95%CI 0.98–0.99) for non-accidental mortality, and 0.95 (95%CI 0.93–0.98) and 0.97 (95%CI 0.96–0.99) for respiratory mortality. For perceived neighborhood green space, HRs were 0.93 (95%CI 0.92–0.94) and 0.94 (95%CI 0.91–0.98) for non-accidental and respiratory mortality, respectively. The observed lower mortality risks associated with residential exposure to green space were largely independent from exposure to ambient air pollutants. Conclusion: We observed evidence for lower mortality risk in associations with long-term residential exposure to green space in most but not all studied causes of death in a large representative cohort for the five largest urban areas in Belgium. These findings support the importance of the availability of residential green space in urban areas.

For 1 year now, the world is undergoing a coronavirus disease-2019 (COVID-19) pandemic due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The most widely used method for COVID-19 diagnosis is the detection of viral RNA by RT-qPCR with a specific set of primers and probe. It is important to frequently evaluate the performance of these tests and this can be done first by an in silico approach. Previously, we reported some mismatches between the oligonucleotides of publicly available RT-qPCR assays and SARS-CoV-2 genomes collected from GISAID and NCBI, potentially impacting proper detection of the virus. In the present study, 11 primers and probe sets investigated during the first study were evaluated again with 84,305 new SARS-CoV-2 unique genomes collected between June 2020 and January 2021. The lower inclusivity of the China CDC assay targeting the gene N has continued to decrease with new mismatches detected, whereas the other evaluated assays kept their inclusivity above 99%. Additionally, some mutations specific to new SARS-CoV-2 variants of concern were found to be located in oligonucleotide annealing sites. This might impact the strategy to be considered for future SARS-CoV-2 testing. Given the potential threat of the new variants, it is crucial to assess if they can still be correctly targeted by the primers and probes of the RT-qPCR assays. Our study highlights that considering the evolution of the virus and the emergence of new variants, an in silico (re-)evaluation should be performed on a regular basis. Ideally, this should be done for all the RT-qPCR assays employed for SARS-CoV-2 detection, including also commercial tests, although the primer and probe sequences used in these kits are rarely disclosed, which impedes independent performance evaluation.

Infectious diseases remain a serious public health concern globally, while the need for reliable and representative surveillance systems remains as acute as ever. The public health surveillance of infectious diseases uses reported positive results from sentinel clinical laboratories or laboratory networks, to survey the presence of specific microbial agents known to constitute a threat to public health in a given population. This monitoring activity is commonly based on a representative fraction of the microbiology laboratories nationally reporting to a single central reference point. However, in recent years a number of clinical microbiology laboratories (CML) have undergone a process of consolidation involving a shift toward laboratory amalgamation and closer real-time informational linkage. This report aims to investigate whether such merging activities might have a potential impact on infectious diseases surveillance. Influenza data was used from Belgian public health surveillance 2014–2017, to evaluate whether national infection trends could be estimated equally as effectively from only just one centralized CML serving the wider Brussels area (LHUB-ULB). The overall comparison reveals that there is a close correlation and representativeness of the LHUB-ULB data to the national and international data for the same time periods, both on epidemiological and molecular grounds. Notably, the effectiveness of the LHUB-ULB surveillance remains partially subject to local regional variations. A subset of the Influenza samples had their whole genome sequenced so that the observed epidemiological trends could be correlated to molecular observations from the same period, as an added-value proposition. These results illustrate that the real-time integration of high-throughput whole genome sequencing platforms available in consolidated CMLs into the public health surveillance system is not only credible but also advantageous to use for future surveillance and prediction purposes. This can be most effective when implemented for automatic detection systems that might include multiple layers of information and timely implementation of control strategies.

IntroductionPatients suffering from Sickle Cell Disease (SCD) are at increased risk for complications due to influenza virus. Annual influenza vaccination is strongly recommended but few clinical studies have assessed its immunogenicity in individuals with SCD. The aim of this study was to explore the biological efficacy of annual influenza vaccination in SCD patients by characterizing both their humoral and cell-mediated immunity against influenza antigen. We also aimed to investigate these immunological responses among SCD individuals according to their treatment (hydroxyurea (HU), chronic blood transfusions (CT), both HU and CT or none of them).MethodsSeventy-two SCD patients (49 receiving HU, 9 on CT, 7 with both and 7 without treatment) and 30 healthy controls were included in the study. All subjects received the tetravalent influenza α-RIX-Tetra® vaccine from the 2016-2017 or 2017-2018 season.ResultsProtective anti-influenza HAI titers were obtained for the majority of SCD patients one month after vaccination but seroconversion rates in patient groups were strongly decreased compared to controls. Immune cell counts, particularly cellular memory including memory T and memory B cells, were greatly reduced in SCD individuals. Functional activation assays confirmed a poorer CD8+ T cell memory. We also document an imbalance of cytokines after influenza vaccination in SCD individuals with an INFγ/IL-10 ratio (Th1-type/Treg-type response) significantly lower in the SCD cohort.ConclusionSCD patients undergoing CT showed altered immune regulation as compared to other treatment subgroups. Altogether, the cytokine imbalance, the high regulatory T cell levels and the low memory lymphocyte subset levels observed in the SCD cohort, namely for those on CT, suggest a poor ability of SCD patients to fight against influenza infection. Nevertheless, our serological data support current clinical practice for annual influenza vaccination, though immunogenicity to other vaccines involving immunological memory might be hampered in SCD patients and should be further investigated.

This paper describes a dataset of 6284 land transactions prices and plot surfaces in 3 medium-sized cities in France (Besançon, Dijon and Brest). The dataset includes road accessibility as obtained from a minimization algorithm, and the amount of green space available to households in the neighborhood of the transactions, as evaluated from a land cover dataset. Further to the data presentation, the paper describes how these variables can be used to estimate the non-observable parameters of a residential choice function explicitly derived from a microeconomic model. The estimates are used by Caruso et al. (2015) to run a calibrated microeconomic urban growth simulation model where households are assumed to trade-off accessibility and local green space amenities.

The current COronaVIrus Disease 2019 (COVID-19) pandemic started in December 2019. COVID-19 cases are confirmed by the detection of SARS-CoV-2 RNA in biological samples by RT-qPCR. However, limited numbers of SARS-CoV-2 genomes were available when the first RT-qPCR methods were developed in January 2020 for initial in silico specificity evaluation and to verify whether the targeted loci are highly conserved. Now that more whole genome data have become available, we used the bioinformatics tool SCREENED and a total of 4755 publicly available SARS-CoV-2 genomes, downloaded at two different time points, to evaluate the specificity of 12 RT-qPCR tests (consisting of a total of 30 primers and probe sets) used for SARS-CoV-2 detection and the impact of the virus’ genetic evolution on four of them. The exclusivity of these methods was also assessed using the human reference genome and 2624 closely related other respiratory viral genomes. The specificity of the assays was generally good and stable over time. An exception is the first method developed by the China Center for Disease Control and prevention (CDC), which exhibits three primer mismatches present in 358 SARS-CoV-2 genomes sequenced mainly in Europe from February 2020 onwards. The best results were obtained for the assay of Chan et al. (2020) targeting the gene coding for the spiking protein (S). This demonstrates that our user-friendly strategy can be used for a first in silico specificity evaluation of future RT-qPCR tests, as well as verifying that the former methods are still capable of detecting circulating SARS-CoV-2 variants.

CRISPR/Cas9 efficiently induces targeted mutations via non-homologous-end-joining but for genome editing, precise, homology-directed repair (HDR) of endogenous DNA stretches is a prerequisite. To favor HDR, many approaches interfere with the repair machinery or manipulate Cas9 itself. Using Medaka we show that the modification of 5’ ends of long dsDNA donors strongly enhances HDR, favors efficient single-copy integration by retaining a monomeric donor conformation thus facilitating successful gene replacement or tagging.

This paper studies clusters in the logistics sector. Like traditional cluster research, indicators of concentration to detect co-location of employment are calculated. However, this approach is enhanced by including a quantitative analysis of the inter-firm relations between logistics companies through the use of a community detection algorithm on a microeconomic dataset of buyer-supplier relations. Combining both results in a typology of logistics clusters. Next to the big clusters characterized by employment concentration and many internal and external relations, spill-over and polycentric clusters are identified. This approach seems promising to detect in future research clusters in other sectors and places

Using conventional relational data (residential migrations, commutes to and from the workplace) and less conventional relational data (mobile telephony calls), the space in and around the Brussels-Capital Region is partitioned into groups of closely inter-related places using a mathematical community detection method. The partitions obtained lead to strong spatial structures, while neither the distance nor the characteristics of the places are taken into account in this method. This article illustrates how large databases (big data) and their specific methods provide new opportunities for urban analyses (delimitation of urban borders, formalisation of intra-urban structures), and remind us here that no structure may be interpreted without a thorough understanding of data, the tools used and regional and urban theories.

Using conventional relational data (residential migrations, commutes to and from the workplace) and less conventional relational data (mobile telephony calls), the space in and around the Brussels-Capital Region is partitioned into groups of closely inter-related places using a mathematical community detection method. The partitions obtained lead to strong spatial structures, while neither the distance nor the characteristics of the places are taken into account in this method. This article illustrates how large databases (big data) and their specific methods provide new opportunities for urban analyses (delimitation of urban borders, formalisation of intra-urban structures), and remind us here that no structure may be interpreted without a thorough understanding of data, the tools used and regional and urban theories.

Using conventional relational data (residential migrations, commutes to and from the workplace) and less conventional relational data (mobile telephony calls), the space in and around the Brussels-Capital Region is partitioned into groups of closely inter-related places using a mathematical community detection method. The partitions obtained lead to strong spatial structures, while neither the distance nor the characteristics of the places are taken into account in this method. This article illustrates how large databases (big data) and their specific methods provide new opportunities for urban analyses (delimitation of urban borders, formalisation of intra-urban structures), and remind us here that no structure may be interpreted without a thorough understanding of data, the tools used and regional and urban theories.

This paper proposes an empirical analysis of the sensitivity of Discrete Choice Model (DCM) to the size of the spatial units used as choice set (which relates to the well-known Modifiable Areal Unit Problem). Job's location choices in Brussels (Belgium) are used as the case study. DCMs are implemented within different Land Use and Transport Interactions (LUTI) models (UrbanSim, ILUTE) to forecast jobs or household location choices. Nevertheless, no studies have assessed their sensitivity to the size of the Basic Spatial Units (BSU) in an urban context. The results show significant differences in parameter estimates between BSUs. Assuming that new jobs are distributed among the study area proportionally to the utility level predicted by the DCM for each BSU (as in a LUTI model), it is also demonstrated that the spatial distribution of these new jobs varies with the size of the BSUs. These findings mean that the scale of the BSU used in the model can influence the output of a LUTI model relying on DCM to forecast location choices of agents and, therefore, have important operational implications for land-use planning.

The objective is to refresh the geography of Belgium using interactions between places by means of a community detection algorithm (Louvain Method) inspired by Complex theory and Data Sciences. Places that are tightly related are optimally clustered into communities, leading to a new and optimal partition of Belgium. Migrations and commuting movements (Census11) are here analysed. We obtain a mosaic of “interaction fields” that are here interpreted in terms of methodological choices, human and urban geography as well as Belgian political dilemmas. They give the opportunity to remind that researchers have to control the impact of their methodological choices and that each type of data leads to a different geographical partitioning, with one major unexpected common spatial feature in Belgium: the pre-eminence of the provincial borders. This perfectly fits with current political questioning.

This paper aims to compare the spatial distributions of road accidents involving a cyclist that are officially reported to the police with those not reported (user-sourced dataset). We show that reported and unreported cycling accidents have similar spatial patterns and exhibit similar locational tendencies with respect to specific infrastructures and facilities. We illustrate the importance of defining a study area in the interpretation of the (cross) K-function results and show that cycling accidents are more likely to be unreported in areas where a small speed difference between slow and fast modes is imposed (traffic-calming areas). Because safety measures influence both accident rate and reporting rate, evaluation of their effect on cycling accidents requires careful spatial analysis.

The aim of this paper is to assess the reliability of policy evaluation based on Land Use and Transport Interactions models, relative to the choice of the Basic Spatial Units. An UrbanSim (+ MATsim) model applied to Brussels (Belgium) is used as the case study. The evolution of the study area over twenty years is forecasted for four levels of Basic Spatial Units and five scenarios (businessas-usual and four alternatives). Results show larger variations between Basic Spatial Units levels than across scenarios. These findings are valid for various sustainability indicators and for a simple cost-benefit analysis aiming at ranking the scenarios. The direction of the variations resulting from the implementation of the scenarios remains, however, the same for all Basic Spatial Units levels. Hence, the influence of the scale on policy evaluation based on Land Use and Transport Interactions models appears limited when it is only intended to compare scenarios, but it will have a crucial role when evaluations are based on absolute variations or threshold values.

The daily commute is still the main source of traffic congestion. Despite transport research emphasis on commuters, the work end of home to work travel receives less attention. However, employers influence the commute behaviour of employees in different ways. The Belgian database Home-to-Work-Traffic (HTWT) contains information on accessibility, work regimes and mobility management initiatives of 7460 worksites of large employers in Belgium. In a spatial multilevel regression model both contextual and worksite factors are incorporated to investigate the share of cycling employees. While controlling for different economic, physical and other factors, the provision of bicycles by the employer seems to be successful, while the effect of bicycle facilities is less clear, partly due to the fact that bicycle facilities are more popular in less cycle-friendly areas.

This paper assesses the usability of land prices as an indicator of the efficiency by which different delineations of a given city capture the influence area of that city. The case study used is Brussels (Belgium). A hedonic model of land prices (log-linear and semi-parametric specifications) is estimated for 12 different delineations of the city and on automatically constructed delineations. The assumption, grounded in the Alonso-Muth model, is that when local amenities have been controlled for, accessibility to the CBD parameter estimate will reflect the city influence on its delineation. Results show that both the size and composition of the delineations of Brussels influence the land price determinants. The size changes the spatial structure of land prices, which is best described by Hoyt’s sector model for narrow definitions of Brussels, and by Alonso-Muth type model for larger definitions. Composition induces variations in the magnitude of the influence of accessibility to the CBD on land prices, due to the presence of secondary centers or rural areas. The lack of detailed data on land prices limits the robustness of the results. Nevertheless, our findings show the potential of land prices as a tool for comparing delineations of a city, or to draw delineations of that city. Finally, they also suggest that delineations based on fluxes (e.g. commuting), and on endogenous thresholds, are more adequate to capture the influence area of a city than those based on transport infrastructure or administrative delineations.

In this paper, we aim at exploring how individual location decisions affect the shape of a growing city and, more precisely, how they may add up to a configuration that diverges from equilibrium configurations formulated ex-ante. To do so, we provide a two-sector city model merging a static equilibrium analysis with agent-based simulations. Results show that under strong agglomeration effects, urban development is monotonic and ends up with circular, monocentric long-term configurations. For low agglomeration effects however, elongated and multicentric urban configurations may emerge. The occurrence and underlying dynamics of these configurations are also discussed regarding commuting costs and the distance-decay of agglomeration economies between firms. To sum up, our paper warns urban planning policy makers against the difference that may stand between appropriate long-term perspectives, represented here by analytic equilibrium configurations, and short-term urban configurations, simulated here by a multi-agent system.

This paper presents the results of the survey conducted under the auspices of the Belgian National Committee of Geography. The survey focused on the present employment and complementary studies of Belgian geography alumni of all Belgian universities that graduated before 2003. With respect to employment and to a large extent with respect to complementary studies and degrees, it is shown that the trend of obtaining a teacher’s certificate is declining as well as of being employed in secondary and higher education. By contrast, spatial and regional planning, research and consulting, GIS, and ecology and environmental management have gained considerable interest as potential fields of employment outside education. The proportion of geography graduates being unemployed remains very low. This should keep the field quite attractive in the coming years.

We report the isolation and characterization of a highly pathogenic avian influenza A/H5N1 virus from Crested Hawk-Eagles smuggled into Europe by air travel. A screening performed in human and avian contacts indicated no dissemination occurred. Illegal movements of birds are a major threat for the introduction of highly pathogenic avian influenza.

This paper uses on-line railway travel requests from the iRail schedule-finder application for assessing the suitability of that kind of big data for transportation planning and to examine the temporal and regional variations of the travel demand by train in Belgium. Travel requests are collected over a two-month period and consist of origin-destination flows between stations operated by the Belgian national railway company in 2016. The Louvain method is applied to detect communities of tightly-connected stations. Results show the influence of both the urban and network structures on the spatial organization of the clusters. We also further discuss the implications of the observed temporal and regional variations of these clusters for transportation travel demand and planning.

This article presents the first results of a survey on the occupations of geographers, conducted by the Belgian National Committee of Geography. Among those who graduated in geography from Belgian universities between 1970 and 1998, 47% now teach in secondary or higher education, 47% are employed elsewhere, 5% do not work and are currently not looking for a job and only 1% are registered as unemployed. Recently, the proportion of people employed outside education has strongly increased. Geographical studies lead hardly ever to unemployment.

The period covered by this bibliographical review (1995-2000) is characterized by an important development of the theoretical researches in transport geography. This new trend is illustrated by a great diversity of materials, which can be divided into three sub-groups: network analysis, modelling techniques and spatial analysis of road transport externalities. But a significant part of papers with a strong descriptive component indicates that empirical studies still constitute a concern of the Belgian geographers, especially in connection with new research areas as the developing world and the geography of cruise shipping.

Two recent techniques are here used to delineate the urban agglomeration of Brussels : a fractal methodology for extracting the border between urban and not-urban surfaces, and a network analysis based on modularity applied on two different interaction matrices (telephone fluxes, commuting). In order to define spatial subsets in which relationships between places are more intense. These methods have the advantage of not depending upon a priori defined thresholds : thresholds are fixed by the methods and data themselves (endogenous). These methods have been applied on the entire territory of Belgium (Blondel, Krings and Thomas, 2010 ; Tannier and Thomas, 2012) and are here discussed for Brussels only. Results are further compared to more traditional delineations. Observed differences are mainly observed at the outskirts of the agglomeration but are very important in terms of policy : the urban-rural limit depends upon the criterion (definition, threshold) and method used. The two methods used here have the advantage of not depending upon arbitrary choices.

Setting out from an analysis of the notion of the call in the works of Lévinas and his adherents, my task will be to show how that which is presented as description of a phenomenon is in fact the deconstruction of the text of tradition. In order to accomplish this, it will be apposite first to carry out an overview of the uses of the notion of the call in order to flesh out its recurring constants; subsequently, it will become possible to demonstrate the ways in which description is entirely dependent on a prerequisite act of deconstruction. That phenomenological description should thus be dependent on deconstruction explains why, in all theses texts, the notion of the call is a description of trauma which cannot account for all the dimensions of the call—such as the artistic dimension of the call exemplified by Alberti and analysed here through the example of Carvaggio's The Calling of Saint Matthew.

Numerous cities are pursuing large urban projects in order to consolidate both their international reputation and their position in an increasing context of competition between cities. These complex projects involve a multitude of stakeholders; that is, groups or individuals that can affect or be affected by the objectives of the project, including public officers, investors, the civil society, professionals, etc. The comparative analysis of the organizational structure (the set of stakeholders and the relationships between them) and management mechanisms (strategic tools, tactical urban planning methods, tools for citizen participation) in two large urban projects – the Quartier des spectacles in Montreal (Canada) and Lyon Confluence (France) – shows how this structure and these mechanisms determine the level of influence of the different stakeholders on the project. Despite the fact that participation has contributed to informing citizens, building trust, and making decision, the study shows that in both cases, strategic decisions were taken by « urban elites » (Pinson, 2009). Although these « urban elites » are composed by a multiplicity of actors, public authorities in Lyon largely dominate the urban project, whereas in Montreal the project is dominated by both public and private urban elites. Finally, the study highlights the advantages and disadvantages of participation models proposed by S. Arnstein (1969) and UN-Habitat (2009).

In this article, we examine the existence of regions and borders in Belgium by means of an original data set of more than 200 million mobile communications and a mathematical method which allows networks to be divided into coherent groups in a natural and automatic manner. A geography of mobile communications is thus proposed based on the relative frequency of communications as well as their average duration. In the case of the relative frequency of communications, we obtain a map of Belgium composed of 17 groups or “telephone areas” that each contain only adjacent municipalities. On this first map, the area of Brussels is the only one which runs across the linguistic border and covers the three institutional regions of the country. In the case of the average duration of communications, we obtain a group in the north and a group in the south of the country. These two groups concentrate within themselves almost 98% of telephone calls; only 2% of communications are from one group to the other. The group in the south includes the 19 municipalities of Brussels, all of the municipalities in the Walloon region as well as eight municipalities with facilities located in the Flemish region. In particular, all of the municipalities with facilities in the outskirts of Brussels (with the exception of Wemmel) are part of the group in the south of the country.

In this article, we examine the existence of regions and borders in Belgium by means of an original data set of more than 200 million mobile communications and a mathematical method which allows networks to be divided into coherent groups in a natural and automatic manner. A geography of mobile communications is thus proposed based on the relative frequency of communications as well as their average duration. In the case of the relative frequency of communications, we obtain a map of Belgium composed of 17 groups or “telephone areas” that each contain only adjacent municipalities. On this first map, the area of Brussels is the only one which runs across the linguistic border and covers the three institutional regions of the country. In the case of the average duration of communications, we obtain a group in the north and a group in the south of the country. These two groups concentrate within themselves almost 98% of telephone calls; only 2% of communications are from one group to the other. The group in the south includes the 19 municipalities of Brussels, all of the municipalities in the Walloon region as well as eight municipalities with facilities located in the Flemish region. In particular, all of the municipalities with facilities in the outskirts of Brussels (with the exception of Wemmel) are part of the group in the south of the country.

In this article, we examine the existence of regions and borders in Belgium by means of an original data set of more than 200 million mobile communications and a mathematical method which allows networks to be divided into coherent groups in a natural and automatic manner. A geography of mobile communications is thus proposed based on the relative frequency of communications as well as their average duration. In the case of the relative frequency of communications, we obtain a map of Belgium composed of 17 groups or “telephone areas” that each contain only adjacent municipalities. On this first map, the area of Brussels is the only one which runs across the linguistic border and covers the three institutional regions of the country. In the case of the average duration of communications, we obtain a group in the north and a group in the south of the country. These two groups concentrate within themselves almost 98% of telephone calls; only 2% of communications are from one group to the other. The group in the south includes the 19 municipalities of Brussels, all of the municipalities in the Walloon region as well as eight municipalities with facilities located in the Flemish region. In particular, all of the municipalities with facilities in the outskirts of Brussels (with the exception of Wemmel) are part of the group in the south of the country.

The renewed interest for sustainable transport in Europe is often labelled as mobility management. With this, major attention goes towards the role of employers in the commuting behaviour of their employees. Indeed, employers can encourage a more sustainable commuting by the promotion of alternative modes, like public transport, carpooling and/or cycling, by the designation of an Employee Transport Coordinator, through their location policy, and/or by adapting work schedules and the organisation of telework. An overview of these measures is followed by an analysis of the Belgian situation. The Belgian 2005 questionnaire Home-to-WorkTravel (HTWT) enables us to make an inventory of mobility management in Belgium. The database HTWT contains information on 7460 worksites. Besides having data on modal split, work regimes and accessibility problems, 38 different mobility management measures are checked in the questionnaire. Given that we assume a relationship between accessibility problems and sustainable commuting measures both are incorporated in one analysis. Binary exploratory factor analysis (EFA) is used to make a classification and to obtain a better insight in the structure of the variables. However, no strong link between accessibility problems on the one hand and sustainable commuting measures on the other hand could be detected. Despite the absence of this link, a classification of mobility management measures and accessibility problems has been made. This indicates that employers regularly choose to implement a set of related sustainable commuting measures.

In order to understand patterns of urban commuter flows, insight is required into urban spatial structure (and vice versa). The present contribution first provides a concise overview of the theoretical perspectives from which economists and geographers approach commuting issues. Subsequently, the focus shifts to the classical spatial-economic urban models and how they explain commuter movements. We conduct a number of cluster analyses from which we are able to derive a commuting typology of city region areas. We conclude that distance (which also comprises journey time and proximity of traffic infrastructure), housing characteristics, housing environment, and income continue to play key roles in commuting patterns in the metropolitan areas under consideration.

This paper aims at showing how the estimations of individual shopping travel behavior depends upon the city. To this end, we use nested multinomial logit models with random coefficients, and apply them to shopping trips in four different Belgian cities (Aalst, Antwerpen, Mechelen and Gent). Results highly depend upon the studied city: spatial behavior is influenced by the size and morphology of the city. These results are quite important when starting a data collection step, which is often expensive and time consuming. Large samples are necessary, and one needs to be careful when generalizing from only one case study. Space matters.

Fractal dimension is used to measure the spatial arrangement (morphology) of built-up areas within a Nuts1 region (Wallonia, Belgium) and, more particularly, to test to what extent fractal dimension is related to some variables commonly used in urban economics/urban geography to characterise built environment, housings and residential choice (such as land price, housing rentals, history of urbanisation, type of housing). Special attention is put on the link with the perception of the built environment by households. A multivariate analysis concludes the paper. It is shown that fractal indices differ from other indicators and are very useful for characterizing and understanding built landscapes, as well as for modelling and planning urban realities.

Il s’agit, dans cet article, de faire saillir les traits les plus marquants de la pensée économique de Fichte. On montre que l’organisation du marché et des échanges en général participe d’une vision franchement étatique et protectionniste. Mais l’interventionnisme de l’État a pour fondement la théorie juridique de la propriété comme espace de liberté. Si communisme fichtéen il y a, il s’agit d’un communisme de la liberté, conçu comme répartition des sphères d’action. Là est sans doute l’un des traits les plus originaux de Fichte puisque la mise en commun propre à la notion de communisme ne repose pas sur l’idée d’une égalité stricte entre les citoyens, mais bien plutôt sur l’idée de la liberté de chacun d’entre eux. L’étatisme a paradoxalement ici pour fondement une certaine forme d’individualisme. En un mot, toujours plus de liberté égale toujours plus d’État.